In recent years, domestic robots such as pet robots have been developed extensively. More practical domestic robots such as housekeeping support robots are expected to be implemented in the future. Such a domestic robot is utilized in a home and needs to coexist with a human being. The domestic robot thus inevitably comes into physical contact with the human being and needs to be flexible in terms of safety.
In plants, automation has been progressing in assembling work or dismantlement work for recycling. Conventional industrial robots are hardly useful if the work is complicated or the environment is not simple in which tools such as jigs are hard to be used and components are placed at different positions in small lot production in great varieties or the like. To the contrary, there have been proposed work support robots that assist mainly working of human beings so as to improve work efficiency. Such a robot assisting a human being operates near the human being, and thus needs to be flexible in terms of safety.
As a flexible robot, there has been developed a pneumatic arm that is driven by a pneumatic artificial muscle as a pneumatic actuator. The pneumatic arm utilizing air compressibility has mechanical flexibility and is essentially safe in comparison to a case of performing control so as to realize flexibility.
The pneumatic artificial muscle is configured by an elastic body and thus has a problem of large aging variation due to contraction or a load.
In order that a control system deals with such aging variation of an actuator in a mechanism driven by the actuator, JP 2000-95107 A proposes a conventional technique in which a damping apparatus for reducing vibration of a vehicle supported by a bogie truck with use of a hydraulic actuator improves damping performance by identification of an actuator motion model.